Commonly, car headlights are triggered with relays. I'm fine with that, but, I just dislike the way the contacts wears out over time.
Solid State Relay (SSR) are already in the market, but tend to be quite pricey.
About five years ago, I'm using my PC as signal generator, and this speaker amp to drive a transistor, which is then driving an ignition coil. I'm using only the left-channel at that time.
While having fun, for maybe about 3 months, boring with just 12V supply, I tried 24V. It ran for few minutes, then, ..., silence... I blew my amp! Feeling guilty, I decided to stop play with it for a while.
Listening music with only my right ear for quite some time, I decided to play with it again.
And yes, now the both of the channels are burnt!
With some few limited spare time, I try to revive it back.